A. Field of the Invention
This invention relates to the hydration of liquid polymers and, more particularly, to a novel apparatus and its use in the hydration of liquid polymers.
B. Description of the Prior Art
Liquid polymers are increasingly used as flocculating agents in many water and waste treatment installations. For example, liquid polymers may be used in water treatments such as raw water clarification, municipal and industrial waste water clarification, chemical process water purification and emulsion breaking.
For such uses, it is usually necessary that the commercially-available, concentrated liquid polymer solutions and dispersions be first hydrated to form a dilute aqueous solution having less than about 1.09% by weight liquid polymer present. However, much care is normally necessary for such hydration. In particular, the mixing time and relative amounts is usually closely controlled to avoid the formation of a water-insoluble gelatinous mass of polymer which can lead to a waste of chemical and clogged process lines. Furthermore, the velocity during hydration is also normally controlled so as to not cause agitation that may shear apart the polymer chains and thereby reduce the effectiveness of the polymer.
In general, proposed prior art methods of hydrating liquid polymers include "in-line" mixers which make use of helix configurations inside a section of pipe. See, for example, Kenics Corporation sales brochure entitled "STATIC MIXER MODULES--DESIGN BULLETIN" effective Mar. 1, 1974; Kenics Corporation technical report entitled "OPERATION OF STATIC MIXER UNITS", 1976; and Komax Systems, Inc., sales brochure entitled "PROCESS CONTROL MOTIONLESS MIXING" Bulletin 103, effective September, 1976. However, such designs may not provide the close control of polymer hydration that is needed to prevent the problems of insoluble mass formation and polymer shearing. Batch-type mixers have also been proposed for hydrating liquid polymers. However, such apparatus requires large tanks and careful addition of the polymer to the water in order to prevent the formation of insoluble gelatinous masses.